Light a Global Terrain Map

This example shows how to create a global topographic map and add a local light. The example also shows how to change the material and lighting properties and add a second light source.

Load the topo DTM files, and set up an orthographic projection.

load topo
axesm('mapprojection','ortho','origin',[10 -20 0])
axis off

Plot the topography and assign a topographic colormap.


Add a local light at a distance of 250 km above New York City, (40.75°N, 73.9°W). The first two arguments to lightm are the latitude and longitude of the light source. The third argument is its altitude, in units of Earth radii.


Because the surface is quite dark, add more reflectivity by using the material function.

material([0.7270  1.0  1.0  4.0000  0.9925]) 
lighting Gouraud; hidem(gca)

Add more lights. This example adds a second light, colored magenta, and positioned over the Gulf of Arabia.